Due to the high manufacturing cost of Nickel based alloy compressor blisks, aero engine repairing process research has important engineering significance and economic value. Inconel718 Ni-based superalloy has the advantages of irradiation, corrosion resistance and excellent mechanical and processing properties. In this paper, a production process for the laser additive and subtractive hybrid manufacturing technologies was presented to repair a microcrack of Inconel 718. The whole repairing process includes four steps. Firstly, a pulsed laser was used to clean and etch the crack through materials subtractive. Secondly, a high-power continuous wave laser was used to additive material in the crack by laser deposition. Thirdly, a pulsed laser was applied to remove the excess repair material. Finally, a fiber laser was used to polish surface. The results showed that defect-free repair samples can be obtained with proper processing parameters. Metallurgical bonding could be achieved between the melting Inconel718 powder and the substrate under the action of a high-energy laser beam. The columnar dendrite and inter-dendritic structure in the repair zone are epitaxially grown along the deposition direction. The microstructure in the repair zone was fine and uniform due to the high gradient, high-speed solidification characteristics of the laser rapid fusion. The micro-hardness of the repaired tissue reduced to about 87% of the matrix and there was no new phase produced in the repair zone.
In this paper, the laser cladding method was used to preparation the TiC reinforced Ni-Fe-Al coating on the Ni base superalloy. The Ti/Ni-Fe-Al powder was preset on the Ni base superalloy and the powder layer thickness is 0.5mm. A fiber laser was used the melting Ti/Ni-Fe-Al powder in an inert gas environment. The shape of the cladding layer was tested using laser scanning confocal microscope (LSCM) under different cladding parameters such as the laser power, the melting velocity and the defocused amount. The microstructure, the micro-hardness was tested by LSCM, SEM, Vickers hardness tester. The test result showed that the TiC particles was distributed uniformly in the cladding layer and hardness of the cladding layer was improved from 180HV to 320HV compared with the Ni-Fe-Al cladding layer without TiC powder reinforced, and a metallurgical bonding was produced between the cladding layer and the base metal. The TiC powder could make the Ni-Fe-Al cladding layer grain refining, and the more TiC powder added in the Ni-Fe-Al powder, the smaller grain size was in the cladding layer.
Current spectroscopic detector crystals contain defects that prevent economic production of devices with sufficient
energy resolution and stopping power for radioisotope discrimination. This is especially acute for large monolithic
crystals due to increased defect opportunity. The proposed approach to cost reduction starts by combining stereoscopic
IR and ultrasound (UT) inspection coupled with segmentation and 3D mapping algorithms. A "smart dicing" system
uses "random-access" laser-based machining to obtain tiles free of major defects. Application specific grading matches
defect type to anticipated performance. Small pieces combined in a modular sensor pack instead of a monolith will
make the most efficient use of wafer area.